1. Field of the Invention
The present invention relates to a transparent conductor.
2. Related Background Art
A panel switch such as a touch panel is generally constituted from a pair of transparent electrodes facing one another, and spacers sandwiched between the pair of transparent electrodes or else dot spacers printed on a conductive surface of one of the pair of transparent electrodes. With such a panel switch, upon one of the transparent electrodes being pressed, this transparent electrode contacts the other transparent electrode so that a current flows, whereby the position of the point of contact is detected. Transparent conductors are used as such transparent electrodes, and as such transparent conductors there are ones in which a sputtered film is deposited as a conductive layer on a substrate, and ones in which a conductive layer comprising conductive particles and a binder is formed on a substrate.
However, if such a transparent conductor is used in a touch panel or the like under a high-humidity environment or in an atmosphere of a chemical substance, then the transparent conductor will gradually absorb moisture or the chemical substance, and hence the electrical resistance of the transparent conductor will increase, and furthermore the change over time in this electrical resistance will tend to become greater. If such a transparent conductor is used, for example, in a touch panel or the like and placed under an environment as above, then there will thus be a risk of the operation of the touch panel gradually becoming unstable.
A transparent conductor according to which increase in or change over time in the electrical resistance caused by absorption of moisture or a chemical substance is suppressed is thus desired. For example, there has been proposed a light-transmitting conductive material using a phenoxy resin or a mixed resin of a phenoxy resin and an epoxy resin made to have low hygroscopicity, or polyvinylidene fluoride, as a resin for fixing conductive particles in place (see, for example, Japanese Patent Application Laid-open No. 08-78164, Japanese Patent Application Laid-open No. 11-273874).